In Frozen II, shortly after Anna, Elsa, and friends enter the enchanted forest, Olaf gets separated from the group.
He calls out for his friends, as well as somebody named Samantha, which then causes him to break out laughing when he realizes he doesn’t actually know anybody by that name.
He then begins to experience the strange happenings in the forest, which begin to freak him out, though he is confident that things aren’t as strange as they appear, it must just be because he’s so young that it seems that way.